Interval timer



#lune 3 1969 c. A. BALcHuNAs 3,448;227

INT ERVAL TIMER Filed Aug. 25; 1967 sheet of 2 )fa ...P

'MAMMA [Wye/7X0# f/zaf/es 6. Ear/Mamas June 3, 1969 c. A. BALcHuNAs 3,448,227

INTERVAL TIMER Filed Aug. 23, 1967 sheet 2 of 2.l

iff/H7@ United States Patent O U.S. Cl. 200-39 6 Claims ABSTRACT OF THE DISCLOSURE An interval timer having an output actuator for a device to be controlled, a timing motor, a gear continuously rotated by the timing motor, and a unique timing control and interval setting gear member which is manually movable into mesh with the continuously rotatable gear.

Background of the invention tinuously rotatable -gear simply drives the interval setting gear in the opposite direction back to a position to actuate a switch, alarm or other mechanism. Convenrtionally, such interval timers include additional parts for preventing damage to the motor and gearing when the interval gear is moved into mesh with the continuously rotating gear. For example, as illustrated in U.S. Patent No. 3,033,948 to Boyles dated May 8, 1962, assigned to the same assignee as the present invention, a clutch is provided between a gear train and a continuously rotatable gear to permit movement of the continuously rotatable gear by an interval setting gear without causing a change in the position of clock hands or damaging the gear train. In a prior U.S. Patent No. 3,180,168 to Harris dated Apr. 27, 1965, a relatively complex slotted bearing plate and spring arrangement is provided to prevent damage to a motor or gearing of an interval timer when an interval setting gear is manually operated.

Summary of the invention It is a primary object of my invention to provide a low cost, reliable and simple timing control and interval setting gear arrangement for a timer which eliminates the necessity for an additional clutch or a complex arrangement to prevent damage to a timing motor or gear train.

In accordance with one aspect of my invention, a unique timing control and interval setting gear member is positioned between a continuously rotated gear and an output actuator for a device to be controlled. The timing control and interval gear member includes a hub and a relatively thin toothed portion resiliently connected to the hub which is manually rotatable into and out of mesh with the continuously rotated gear. The interval gear is also sufciently flexible so that when it is moved into mesh with the continuously rotatable gear the tops of the teeth of the interval setting gear and the continuously rotatable gear abut each other and the teeth on the 'continuously rotatable gear temporarily move the toothed portion of the interval gear away from the teeth on the continuously rotatable gear. After the interval setting gear has been rotated to the desired short time interval, the teeth on the interval setting gear are positioned between the teeth on the continuously rotatable gear and the continuously rotatable gear drives the interval gear back to its original position to operate an l3,448,227 Patented June 3, 1969 actuator for a device to be controlled. With this construction, there is no need to provide a clutch or a complex arrangement for preventing damage to the motor or gear train. The unique interval setting gear is suiciently llexible so that it can be rotated relative to the continuously rotatable gear without damaging the gear teeth on the continuously rotatable gear or the gear train and motor. Thus, an extremely simple yet eltective interval gear and control arrangement is provided for an interval timer.

Brief description of the drawings Other specific and attendant advantages of this invention will be apparent from the following description taken in connection with the accompanying drawings in which:

FIG. l is a front perspective view of the interval timer with a portion of the front plate removed to show the timing control and interval gear member;

FIG. 2 is a perspective view of the timing control and interval gear member;

FIG. 3 is a side elevational view of the timing control and interval gear member;

FIG. 4 is a partial front elevational view of a portion of the interval timer illustrated in FIG. l showing the timing control and interval -gear in a timedon position as it moved into mesh with the continuously rotatable gear;

FIG. 5 is a partial front elevational view similar to FIG. 4 showing the interval timer in timed-olf position;

FIG. 6 is similar to FIGS. 4 and 5 but shows the interval timer in manual on position; and

FIG. 7 is a partial top plan view of the interval timer illustrated in FIG. 1.

Description ofthe preferred embodiment Referring now to the drawings and first, particularly to FIG. 1, an interval timer in which my improved control mechanism may be used is driven by a timing mechanism including a self-starting sychronous motor. Portions of the motor stator magnetic core and energizing coil are shown at 1 and 2 respectively. A supporting structure including a front mounting plate 4 and a rear mounting plate 6 arranged generally parallel thereto is provided for supporting the timer mechanism, and as illustrated, a plurality of generally parallel spacer posts 8, 10 and 12 are xed to the mounting plates for holding the plates generally parallel to each other. As illustrated in FIG. 7, the timing motor includes a driving lpinion gear 11 which extends through an aperture in plate 6 for driving gear train 14 and the hands 16 and 18 of a clock. As illustrated generally in FIG. l, a gear train shaft 20 is arranged generally parallel to the spacer posts 8, 10 and 12 and includes a gear 22 which is continuously rotated by the timing motor.

In the embodiment illustrated, an 0n-oli switch 24 isy provided for controlling a device such as a radio or television set. The switch is lixed to the rear supporting plate 6 and includes an actuator 25 which extends through an aperture in the rear plate to a convenient position between the front and rear supporting plates 4 and 6. The switch includes an internal compression spring 24' for normally biasing actuator 25 to the off position illustrated in FIG. 5. In this position, a movable generally circular contact 26 engages only one of the iixed contacts 28 and 30. In the on position, as illustrated in FIG. 4, the circular movable contact 26 is in engagement with both of the fixed contacts 28 and 30 thereby permitting current to llow from one of the Ifixed contacts through the movable contact 26 and then to the other fixed contact.

According to the invention, there is combined with the aforedescribed interval timer elements, a uniquely designed interval setting gear and control member for manually opening or closing the switch, or closing the switch for a short time interval. The control member 32 is illustrated in FIG. 2 and is preferably formed of Delrin7 plastic or other suitable ilexible material which may be readily formed in a molding operation. As shown, the interval setting gear and control member 32 includes a centrally disposed generally cylindrical hub portion 34, cam portions 36, 37 and 52 extending generally radially outwardly from the hub portion for actuating the switch 24, a relatively thin interval sector gear portion 38 for engagement with continuously rotatable gear 22, and a plurality of resilient fingers `40 for exibly mounting the sector gear portion 38 on the hub portion 34. As illustrated, each of the flexible plastic ngers 40 includes a portion 42 which extends radially outwardly from the hub in the vicinity of cam 36, a portion 44 which extends axially from the cam and a portion 46 which extends still further radially outwardly toward the sector gear portion 38. A stub shaft 47 may also be integrally molded with the unique control member for permitting the member to be rotatably mounted in a stamped aperture formed in rear plate 6.

As illustrated more particularly in FIG. 1, the unique control member is mounted so that the cam 36 engages switch actuator 25 and sector gear 38 may be caused to mesh with continuously rotatable gear 22. A manually operable knob 48 and an indicating pointer 50 are iixed to the unique control member 32 for permitting it to be manually rotated and for indicating its relative position.

With my unique flexible gear construction, when the Shaft 48 is turned manually in a oounterclockwise direction, the teeth on sector gearl 38 abut the teeth on continuously rotatable gear 22 as illustrated more particularly in FIG. 4. Continued manual movement of the sector gear causes the teeth to slide on each other and the toothed portion of the sector gear is moved inwardly to the dotted line position illustrated in FIG. 4 wherein the tops of the teeth of the sector gear abut the tops of the teeth on the continuously rotatable gear. Naturally, when the sector gear has been rotated to its desired relative position with respect to the continuously rotatable gear 20 thereby setting the desired short time interval, the teeth on the sector gear assume the solid line position illustrated in FIG. 4 where they are positioned between the teeth of the continuously rotated gear. In this position, the continuously rotated gear 22 drives the sector gear clockwise back to its original position illustrated in FIG. 5 to permit cam 36 to open the switch. With this improved construction, an operator may move the sector gear teeth across the teeth of the meshing continuously rotating gear 22 Without damaging the timing gear train or the timing motor and also without upsetting or changing the time indicated by clock hands 16 and 18. It can be readily appreciated that this is accomplished without the provision of a separate friction clutch to separate the continuously rotating gear 22 from the principal gears of the timing gear train.

In order to achieve a relatively quiet meshing of gears 38 .and 22, -gear 22 may be formed from a llexible polyurethane material instead of hard plastic or metal.

If it is desired to have switch 24 vclosed for operating apparatus such as a radio receiver, and after a lapse of a short time interval, say, minutes, turn ofr" the receiver, the knob 48 is rotated counter clockwise to slide cam portion 3-6 on the top surface of switch actuator 25 from the switch open position illustrated in FIG. 5 to the switch closed position indicated in FIGS. 4 and 1. As shown in FIG. 1, the interval gear 32 has been placed in meshing engagement With continuously rotatable gear 22, and pointed 50 indicates the length of the short time interval which has been set. The continuously rotatable gear 22 then drives the interval setting gear 32 in a clockwise direction back to its original position 'and the switch is snapped open as illustrated in FIG. 5.

In order to move and hold switch actuator 25 in its manual on position, cam 36 includes a portion 52 which is disposed radially outwardly from its manual olf portion 37, and one of the spring lingers includes a flexible latch detent 54 integrally formed therewith. With this construction, when it is desired to turn the switch manually on, knob 48 is rotated clockwise to the position illustrated in FIG. 6 wherein latch detent 54 grips spacer post 56 to hold the switch in the on position.

In order to protect the control member 32 from overtravel in the automatic on direction or the manual on direction, a simple readily formed stop arrangement is achieved without the provision of .additional parts. As illustrated more particularly in FIGS. 7 and 2, a tab 57 extends forwardly from rear plate 6 for cooperation with stop abutments 58 and 6l) which are integrally formed on the cam portion of the unique control member. Stop abutment 60 cooperates with the right side of the tab 57 to prevent overtravel of the control member 32 in the counterclockwise or timed on direction, while stop abutment 58 cooperates with the left side of tab 57 to prevent overtravel in the clockwise or manual on direction.

In view of the foregoing, it can be appreciated that my unique timing control and interval setting gear member is formed from a single piece of plastic material and it accomplishes a plurality of functions. The member includes cam surfaces 36, 37 an-d 52 for moving a switch 24 to its timed-on, manual on or off positions. It includes a latch 54 for holding the control member and switch in manual on position. It includes abutment stops 58 and y60 for preventing overtravel of the control member 32 in either the manual on or timed-on directions. Moreover, it is shaped and designed to provide an interval gear which is suliiciently exible so that it may be moved into engagement'with a continuously rotating gear without causing a change in the time indicated by the interval timer .and without damaging the timer motor or timer gear train. It can also be appreciated that all of this is accomplished without the provision of a separate additional clutch in the timing gear train between the continuously rotated gear and the principal gears of the gear train which drive the hands 1'6 and 18 of the clock.

While there has been shown and described a particular embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein Without Ideparting from the invention, and more specifically, for example, that the switch assembly may be reversed to achieve a timed oft arrangement. With such a construction, cam 52 would move the switch to the manual off position and cam 36 would move the switch to the timed off position.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An interval timer comprising: (a) an output actuator for a device to be controlled; (b) a timing motor; (c) a gear continuously rotated by said timing motor;

and

(d) an integrally formed resilient interval setting gear and control member for operating said actuator at a preset time, said interval setting gear including a hub and a toothed portion, said interval setting gear being manually rotatable into and out of mesh with said continuously rotated gear, and said interval setting gear being suiciently flexible so that when it is moved into mesh with said continuously rotatable gear the tops of the teeth of said interval setting gear and said continuously rotatable gear abut each other and the toothed portion of said interval setting gear is moved with respect to said hub resiliently away from the teeth on said continuously rotatable gear.

2. An interval timer defined in claim 1 wherein said interval setting gear includes a plurality of radially extending llexible lingers integrally connected to said hub and the toothed portion of said interval setting gear.

3. An interval timer comprising:

(a) a pair of mounting plates;

(b) a plurality of generally parallel spacer posts lixed to said mounting plates for holding said plates generally parallel to each other;

(c) a timing motor xed to said mounting plates;

(d) a shaft arranged generally parallel to said spacer posts;

(e) a gear continuously rotated by said timing motor iixed to said shaft;

(f) a switch fixed to one of said mounting plates, said switch having an actuator positioned between said mounting plates; and

(g) an integrally formed interval setting gear and timing control member for moving said switch actuator at a preset time, said timing control and gear member including a hub arranged generally parallel to said shaft and said spacer posts, said hub being mounted for rotation between said mounting plates, -a radially outwardly extending cam surface integrally formed with said hub for slidable actuating movement on said switch actuator, and a relatively thin sector gear portion manually rotatable into and out of mesh with said continuously rotated gear, said sector gear portion being suliiciently exible so that when said sector gear portion is moved into mesh with said continuously rotatable gear the tops of the teeth of said sector gear portion and said continuously rotatable gear abut each other and the teeth on said sector gear portion are moved radially inward by the teeth on said continuously rotatable gear.

4. An interval timer comprising:

(a) a rst and a second mounting plate;

(b) a plurality of generally parallel spacer posts fixed to said mounting plates for holding said plates generally parallel to each other;

(c) a timing motor iixed to said mounting plates;

(d) a shaft arranged generally parallel to said spacer posts;

(e) a gear continuously rotated Iby said timing moto;

iixel to said shaft;

(f) a switch ixed to said rst mounting plate, said switch having an actuator positioned between said mounting plates;

(g) an integrally formed interval setting gear and timing control member for moving said switch actuator at a preset time, said timing control and gear member including a hub arranged generally parallel to said shaft and said spacer posts, a cam extending radially outwardly from the portion of said hub adjacent to said rst mounting plate for slidable actuating movement on said actuator, and a relatively thin sector gear portion including a plurality of spring lingers integrally connected to said hub in the vicinity of said cam, said fingers extending radially outwardly from said hub then axially toward said second mounting plate and then still further radially outwardly to the teeth of said sector gear portion, said sector gear being manually rotatable into and out of mesh with said continuously rotated gear.

5. An interval timer defined in claim 4 wherein a resilient latch is integrally formed on one of said radially extending lingers for cooperating with one of said spacer posts for holding said timing control member in a manual on position.

6. An interval timer defined in claim 4 wherein a tab is integrally formed with said iirst mounting plate and extends inwardly toward said cam, and an abutment stop is integrally formed with said cam lfor cooperating with said tab to limit manual rotation of said control member.

` References Cited UNITED STATES PATENTS 2,886,106 `5/ 1959 Gallagher et al.

3,033,948 5/ 1962 Boyles.

3,180,168 4/ 1965 Harris 74-405 3,199,364 v8/1965 Dew 74-411 3,406,583 10/ 1968 Baier 74-411 ROBERT K. SCHAEFER, Primary Examiner. H. O. JONES, Assistant Examiner. 

